Expression patterns of beta-catenin in in situ and invasive breast cancer.

BACKGROUND

beta-Catenin plays a central role in the E-cadherin/catenin cell-cell adhesion complex and is possibly involved in cellular signalling pathways. In this study, we evaluated the expression patterns of this molecule in in situ and invasive breast cancer.

METHODS

The expression of beta-catenin was evaluated in 121 breast cancer specimens by immunohistochemistry. Its relationship to clinicopathological features was also investigated.

RESULTS

Altered beta-catenin expression was found in 68% of tumours. Lobular carcinomas showed abnormal beta-catenin expression more frequently (77%) than ductal carcinomas (64%) with 46% of lobular cases showing complete absence of beta-catenin immunoreactivity. Cytoplasmic beta-catenin localization was seen only in ductal carcinomas. Aberrant beta-catenin expression was observed in 54% of ductal carcinomas in situ with highly concordant beta-catenin expression patterns in the nearby in situ and invasive components.

CONCLUSIONS

Quantitative and qualitative changes in beta-catenin expression occur in a considerable proportion of in situ and invasive ductal carcinomas and are more prominent in invasive lobular carcinomas.